1. Technical Field
The field relates to network protocols and the World Wide Web.
2. Background
Web browsers are software applications that allow a user to view or download content that is available on a network, such as on a website on the World Wide Web. Content may include text, files, images, audio, video and personal communications. Web pages present such content and are located using uniform resource identifiers (URI) such as a uniform resource locator (URL). Web pages may be retrieved using the Internet Protocol (IP) address of the computer holding the web page content.
Browsers may use a number of protocols and standards to obtain or manage content flow. Most browsers primarily use hypertext transfer protocol (HTTP) to fetch content and web pages. HTTP is an application level protocol providing basic request/response semantics. For example, as shown in FIG. 1, HTTP Requester 110 may send a request, such as for a web page, over network 120. HTTP Responder 130 may receive the HTTP request and return an HTTP response, such as content for the requested web page.
Web pages today usually require multiple subresources, such as images, scripts, video, links, news or other web page content. These subresources are often retrieved from other server domains. Unfortunately, HTTP makes separate requests for each of these subresources. These multiple request/response roundtrips contribute to an accumulated latency that can cause discomfort to users of a web browser.